The vast majority of keyboards in use today for computers are traditional keyboards such as the QWERTY keyboard, the name QWERTY deriving from the first 6 letters of the first row. Other traditional keyboards include the Dvorak keyboard, an alternate arrangement designed to allow faster typing by optimum placement of the keys, and alphabetic keyboards, which are supposed to aid novice users in finding the desired keys. All of these traditional keyboards are distinguished by their characteristic that the user generally presses one key to enter each character. More specifically, these keyboards have a large number of character keys, and one or more shift keys. These shift keys may for example include a traditional upper-case "Shift" key, and also for computer usage other shift keys such as a "Ctrl" key and an "Alt" key. Pressing a character key transmits one character to the computer, but the character transmitted depends on the state of the shift keys. For example, pressing an alphabetic character key without the Shift key pressed will transmit a lower-case character, while pressing the same key with the Shift key pressed will transmit an upper-case character.
In contrast to the traditional keyboards described above, various types of "chord keyboards" have been used and/or proposed. A chord keyboard requires that the user generally press and release more than one key at a time in order to input a character. Chord keyboards have the advantage of requiring fewer keys than traditional keyboards, allowing the keyboards to be smaller, and also benefitting those users who have difficulty with the arm and hand motions required for operation of traditional keyboards.
In order to more clearly distinguish between traditional keyboards with shift keys, and chord keyboards, note that a traditional keyboard's shift keys are well-defined as shift keys, and generally do not input any character to the computer if pressed alone. A traditional keyboard's character keys are distinct from the shift keys, and when multiple key-presses are used on a traditional keyboard only one character key is pressed at a time (along with one or more shift keys). In comparison, although a chord keyboard may also have shift keys, a chord keyboard's character keys are often pressed together in order to generate a character not related to the characters that would be generated if the character keys were to be pressed separately. For traditional keyboards, if the user presses the key that would normally generate an "e" if pressed alone, and also presses the key that would normally generate an "s" if pressed alone, then he is likely to see "es" or "se" on his computer screen. But for a chord keyboard, this combination is likely to be defined as some other unrelated letter, perhaps an "h", not normally associated with either an "e" or an "s".
"Handprint chord keyboards" are a subclass of chord keyboards. A handprint chord keyboard may be strictly defined as one in which the number of keys has been so reduced so as to have only one key for each of the user's fingers. But the term "handprint chord keyboard" is more often used to refer to keyboards with more than one key per finger, but where the most common operations are performed with the primary key available to each finger, and only special operations are performed with the alternate keys for some fingers. A Braille keyboard, with one key for each of three fingers on each hand, and one key shared by the thumbs, is an example of a two-handed handprint chord keyboard as strictly defined with only one key per finger.
Handprint chord keyboards in general are appropriate for users with physical disabilities who cannot easily use a traditional keyboard, but who can operate the much smaller number of keys on the handprint chord keyboard. They are also advantageous for visually impaired or blind individuals, who may find it more difficult to learn to use traditional keyboards than sighted individuals because of their inability to easily find the desired keys on traditional keyboards.
U.S. Pat. No. 4,833,446, Eilam et al, describes a one-handed handprint chord keyboard with eight keys. (This is therefore not a handprint chord keyboard as strictly defined with only one key per finger). This represents the best prior art known for chord keyboards. The present invention will be shown to have numerous advantages over this prior art.
Handprint chord keyboards as strictly defined with only one key per finger would be especially advantageous for users with physical disabilities who might even have trouble moving each finger among its available keys. But chord keyboards which are presently available for computer input either are made as two-handed keyboards, or are provided with more than one key per finger, because it is very difficult to design a usable chord keyboard with only five keys and only one key per finger that can still input to the computer all of the myriad of characters that can be input by a standard computer keyboard. The present invention will accomplish this, where others have not.
A disadvantage of most chord keyboards is that "hunt-and-peck" operation is not possible. On a traditional keyboard, each key is labelled, and the user can hunt for each desired character key, and then press (peck) the key. This allows novice users to commence useful (albeit slow) operation of the keyboard with essentially no training, and then improve their input speed with practice. Although the fastest keyboard users undergo specific training for "touch typing" in order to achieve input speeds in excess of what they would normally achieve simply with practice, many users have not undergone that specific training and are simply former hunt-and-peckers who have increased their input speed with practice.
Some chord keyboards allow hunt-and-peck operation by utilizing only those combinations of keys which consist of adjacent keys, and labelling the keys or the space between them with the corresponding character so as to make it clear what chord (key combination) of adjacent characters is to be pressed for each character. This scheme is very effective, but the restriction of the available chords to only easily marked adjacent key combinations is sufficiently restrictive to require significantly more keys than would otherwise be required for a chord keyboard. Thus, the hunt-and-peck capability of the traditional keyboard is retained, but a significant portion of the advantage of the chord keyboard concept is not obtained.
Expert users of traditional keyboards (touch typists) do not need labelling of the keys, and similarly expert users of chord keyboards do not suffer from lack of labelling of the chord keyboard keys. But it is very important to allow something like hunt-and-peck operation for novice users, so that they can quickly become productive (albeit at a slow input speed). For some occasional users, the ability to use the keyboard at a slow input speed without much prior training is all they will ever need. For many others, eventual improvement of their input speed will be very important, and the ability to use the keyboard at a slow input speed without much prior training will be primarily valuable in that it will provide the user with sufficient incentive to keep working with it until the improvement in input speed is obtained. Also, if the novice user can input slowly, he will learn without seeming to work at learning, especially if the input system is particularly designed so as to guide him in this learning. And the novice user will be guided to learn as he uses the system slowly at first, especially if the novice's mode of operation of the keyboard requires more than just finding a character on a reference card and reading the required chord from the card. The present invention will require instead some small mental effort which is directly involved with the structure of the required chord, providing the novice user with much greater help in learning than he would get from simple use of a reference card. Therefore, a primary purpose of the present invention will be to provide a novice's mode of operation similar to hunt-and-peck operation, for a handprint chord keyboard (or for any type of chord keyboard), which guides the user to learn the system while he uses the novice's mode of operation for actual computer usage. This has been accomplished as will be seen below. Intermediate-level users, as well as novices, will also benefit from this design.
Chord keyboards, which were first proposed decades ago, have not been a commercial success. This is not only because the traditional keyboard established itself as the standard long before chord keyboards were proposed, but probably also because the traditional keyboard is so much more intuitive, that the user is much more comfortable approaching it. The chord keyboard will probably never become an extremely popular item, but with the improvements to the design of the chord keyboard provided by the present invention, as will be described below, the chord keyboard can be made to be much nearer to the intuitive nature of the traditional keyboard, so that those with some particular reason for using a chord keyboard (such as a physical disability which prevents them from comfortably using a traditional keyboard) will be much more likely to find the chord keyboard acceptable.
Various other methods of computer input are also of interest as background to the present invention. These additional methods are generally known as "adaptive software":
"Single switch scanning" is a computer input method which is commonly utilized by a disabled individual using a single switch, in place of a complete keyboard. (This should not be confused with computer input "scanners" of a different type which visually scan a document and input the document into the computer as graphical or textual information. This should also not be confused with the scanning operation of the electronics in almost any conventional keyboard as it interrogates the keys in a sequential fashion, unbeknownst to the user, in order to identify which keys are pressed and which are not pressed.) In a common form of single switch scanning, all of the characters which may be input are displayed on a portion of the computer screen, separated into rows or other forms of groups. The rows are highlighted in sequence at a predetermined rate. When the row containing the desired character is highlighted, the user presses his switch, selecting that row. The characters within the row are then highlighted in sequence at a predetermined rate. When the desired character is highlighted, the user presses his switch, selecting that character, which is input to the computer. This input method is much slower than use of a traditional keyboard or of a chord keyboard. But single switch scanning has the advantage of use by individuals who cannot utilize other keyboards (but can press one switch). Also, novices can learn to use scanning with almost no training, the use of the scanning system being almost as intuitive and straightforward as hunt-and-peck operation of a traditional keyboard. Heretofore, no chord keyboard has been developed which is anywhere near as intuitive as "single switch scanning". But, as will be seen below, the present invention is a chord keyboard that does approach the intuitiveness of "single switch scanning", and this is the most important reason why the present invention is a great advantage over the prior art in chord keyboards.
Their are various adaptive software products that allow a computer user to use a traditional keyboard, but to modify the behavior of the keyboard in order to help overcome some physical disability. For example, "AccessDOS" is computer software provided by IBM to assist disabled users with their computer input efforts with IBM-PC-compatible computers. Its StickyKeys, RepeatKeys, SlowKeys, and BounceKeys functionality falls in this category. For example, the SlowKeys functionality is helpful for a user who tends to tap keys unintentionally while preparing to press another key. It prevents the computer from accepting a key as pressed until it has been pressed for a given time period.
There are also computer access products that allow a computer user to use an external device, not normally part of the computer system, but which is specially connected to the computer system so that the user can input through that device. Again, "AccessDOS" provides a good example. Its "SerialKeys" capability allows a user with an external device to input to the computer system, as long as that external device has a serial port and can transmit appropriate signals through the serial cable to the computer system. The AccessDOS resident software in the computer system makes the computer applications believe that the user is really typing on the computer's regular keyboard.
Another computer input device, often used in addition to the computer keyboard, is the "mouse", the most common version of so-called "pointing devices". The user moves a small device around on the tabletop, and a "mouse cursor" correspondingly moves around on the screen. The mouse also has a small number of "mouse buttons", which are also used for computer input. Various computer access products allow the user to accomplish many of the functions usually accomplished with the "mouse", by operating some of the keyboard keys instead. Again, AccessDOS serves as a good example, with its "MouseKeys" functionality.
AccessDOS, like other adaptive software products that provide these sorts of functionality, does not work under all circumstances with all application programs. But this does not prevent AccessDOS and other similar programs from being invaluable for those disabled persons who need these capabilities. Often, the adaptive software provides them with full access to the application programs they wish to use. Sometimes they must operate application programs in slightly different ways than their able-bodied colleagues, and occasionally they must use different application programs than their able-bodied colleagues because of incompatibilities between the adaptive software and the applications. But AccessDOS and other adaptive software products operate with a large enough majority of computer applications, with little enough requirement to modify the manner in which those computer applications are used, that they are extremely valuable for those with physical disabilities who would have difficulty with their keyboarding if not for the help that the products provide. It is the aim of the present invention to provide this same assistance to many users with physical disabilities who have not found adaptive software products especially suitable for them before this time, in particular to those who have finger dexterity while they they do not have the arm or wrist mobility to use a regular keyboard comfortably. For example, individuals with muscular dystrophy tend to lose their gross motor skills (e.g. arm motion) while still retaining their fine motor skills (e.g. finger motion), and this invention is particularly suitable for such individuals.
Also of interest as background to the present invention is a keyboard designed for typing Japanese or Chinese characters. This is much more difficult than input of characters used in the American language, since there are far more Chinese or Japanese characters. A traditional keyboard for Chinese or Japanese characters, if implemented, would require a great number of keys. Various approaches have been taken to reduce the number of keys on such keyboards. One which is of particular interest here is a keyboard in which the left hand has a small array of shift keys arranged in a pattern, and the right hand has a large number of character keys each of which has a pattern of characters labelled thereon, the pattern of characters corresponding to the pattern of left-hand shift keys. The user utilizes the left-hand shift keys in order to select which character is desired on a particular character key, and then he presses the right-hand character key in order to input that character to the computer. It should be noted that this is not a chord keyboard, but is simply a conventional keyboard with a larger-than-usual number of shift keys, since only one of the right-hand character keys is pressed in order to transmit a character to the computer, and pressing two of the right-hand character keys will likely yield the two characters input sequentially, not a different character entirely. This input method shares a number of important features with "single switch scanning", in that the user first must select a group (by pressing a shift key), and then must select a character from the group (by pressing a character key), with the means for selection of a group or of a character being quite intuitive. This very beneficial feature of both "single switch scanning" and of the Chinese/Japanese keyboard has not heretofore been seen in chord keyboards, probably because it is so difficult to design a computer input system which can merge the chord keyboard concept with the group/character selection concept in an appropriate manner so that the user finds the behavior of the system sufficiently intuitive. As will be seen, the present invention has accomplished this, providing a chord keyboard which is far superior to the prior art.